Isn’t it horrible how much writing advice is cliche?
Yes, there is the craft and logistical and rhythmic stuff that you use to polish whatever rock of words you end up with.
But first you stare at something blank for however long it takes, and look for a way to trick yourself into creating something from nothing, or something from something adjacent, or just to get words on paper, to get that rock that you can polish later.
So you end up with that first and most annoying piece of writing advice.
Just sit there, don’t get too distracted (stare at the wall if you need to), and put one word in front of the other.